Ore concentration



9st. 27, 1931. R. LEE 3,829,565

ORE CONCENTRATION Filed April 20, 1925 Aliel'nating Current Generator Cooling "later WITNESSES INV%R ATTOQNE Y Patented 27, 1931 UNITED STATES PATENT OFFICE BO YAL LEE, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO LEE ENGINEERING RESEARCH CORPORATION, OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN;

ORE CONCENTRATION Application filed April 20, 1925.- Serial No. 24:,51.

vide apparatus for carrying out the method wherein the stream of ore iscaused to fall freely through the alternating field and is there separated into divergent streams falling onopposite sides of a partition.

The invention further consists of the sev-' eral features hereinafter set forth and more particularly defined by the annexed claims.

the accompanying drawing is shown a schematic elevation of apparatus for carrying out the invention, parts being broken away andparts being shown in section.

In the drawing; 10 indicates" a hopper provided with a narrow discharge opening 11 at its bottom. The hopper is' adapted to receive a uantity of ore 12 comminuted to a suitable eness and permitted to drop freely in a thin" sheet or stream 13 from the opening 11 at the bottom of the hopper. i

A receptacle 14 is disposed below the hopper in spaced relation therefrom and is separated by a artition 15 into'compartments 16 and 17. The partition 15 may extend above the receptacle, as shown, and is provided with a thin wedge-shaped upper edge 18. The

partition is so disposed with respect to the opening 11 of the hopper that the ore stream 13 falling from the pper when not acted upon by a-teral forces, ass closely to the left of the partition, as s own, and into the compartment 16. In practice, the comrtments may be merely c utes to effect the lilrther movement of the ore particles.-

The invention contemplates the action of an alternating magnetic field on the freely moving ore stream to separate the conductive from the non-conductive or less conductive particles, this being accomplished by the repellent effect of the field on the conductive particles incident to the production of eddy currents in these particles. In the present instance, I have shown an inductor in the form of a helically wound air core coil 19 arranged on a substantially horizontal axis directed transversely of the falling ore stream 13, the coil being disposed laterally adjacent thefalling ore stream for establishing an alternating magnetic field through which the ore stream may pass. In order to permit the flow of heavy currents in the coil without excessive heating byeddy currents, it may be water-cooled by constructing it of hollow metallic tubing 20 connected to water pipes 21 by suitable insulating couplings 22. The alternating magnetic field, however may be produced in other ways than with the apparatus illustrated.

The coil 19 is supplied with high frequency alternating current from any suitable source 23, which in practice may be a rotary alternator, an arc generator," an oscillatory spark system, or other well known means. The frequency of the alternating current may vary over a wide range, as from 500 to 100,000 cycles, or more, but in general the higher frequencies will be found preferable because of the greater repellent eiiect of thecorresponding alternating field on the conductive particles in the ore stream. Since no ma etizable core is employed for the coil, it is possible, if desired, to use frequencies of several hundred thousand cycles per second, and even more.

In operation, the conductive particles in the ore stream are deflected from their normal vertical path by the repellent effect of the alternating field while the non-conductm particles are unaffected by the field, or i slightly conducting are only slightly defleeted. The ore stream thereupon divides into divergent streams 24 and 25 containing the non-conductive and conductive particles, respectively, and these fall on opposite sides 'of the partition 15 and into respective comwhich the particles possess more than two distinct degrees of conductivity, the stream will separate into more than two divergent streams, which may be suitably collected,

as by providing an additional partition for interposition between adjacent streams. The partition 15 and the hopper 10, and especially those portions thereof adjacent the inducc tor, are preferably made of some non-metallic material in order to avoid bein unnecessarily influenced by the alternating eld.

The provision of a freely alling stream of ore permits the field to act upon it over a.

' of ores, especially minerals not amenable'to magnetic treatment, the invention is also applicablein' general to the separation of metal liferous comminuted masses containing particles possessing different degrees of electrical in the magnetic field.

conductivity. v The term high frequency as herein used means a frequency of such magnitude that it is possible to establish an effective alternating magnetic field without the use of a magnetizable core material.

The term air core as herein used does not exclude the use of dielectrics other than air What I claim as new and desire to secure by Letters Patent is: o

1. In an ore concentrator, the combination of means for producing a freely falling stream of comminuted ore material, and an air core inductor disposed laterally adjacent said-stream with its axis directed transversely thereof for establishing an alternating field acting on conductive particles in said freely falling stream to deflect them laterally from the stream in adirection away from said inductor.

2. In an ore concentrator, the combination of means for producing a freely moving stream of comminuted ore material, an inductor disposed adjacent said stream for establishing an alternating magnetic field acting on conductive particles in said stream for deflecting them laterally from the stream, and a partition ofinsulating material having its upper edge disposed a 'acent said inductor to prevent reminglingo the separated particles in their furt er passagethrough' more remote portions of the field.

3. In an ore concentrator, the combination of means for producing a falling stream of comminuted ore material, andan inductor disposed laterally of said stream for establishing a high frequency alternating magnetic field, acting on said stream to deflect conductive particles laterally from said stream in a directionl away from said inductor, whereby said falling stream is subjected to a relatively large alternating magnetic field and whereby the required energy for separationis relatively small.

4. In an ore concentrator, the combination of means for producing a moving stream of comminuted ore material, and an air core inductor of fluid-cooled tubing disposed adjacent said stream for establishing an alternating magnetic field acting on said stream to deflect conductive particles laterally therefrom. i

5. In a concentrator, the combination ofmeans for producing a moving stream of comminuted metalliferous material,. and an air core inductor disposed adjacent said stream for establishing an alternating magnetic field acting on conductive particles in saidstream to deflect them laterally of said stream, whereby said moving stream is subjected'to a relatively large alternating mag- .neticfield and whereby the required energy for separation is relatively small.

6.'In af concentrator, the combination of means for'producing a freely-moving stream of comminuted electrically-conductive material,.and an air core inductor disposed laterally adjacent said stream with its axis directed transversely thereof for establishingan alternating field acting on conductive particles in said freely-moving stream to deflect them laterally from the stream in a direction away from said inductor.

- 7. In a concentrator, the combination of means for producing a freely-moving stream of comminuted electricall -conducti ve material, and means for pro ucing a high fre-. quency alternating magnetic field acting on .said stream to laterally deflect conductive particles from said stream by the repellent effect of said field on its particles, whereby separation is effected by the use of a comparatively-small amount of energy.

8. In a concentrator, the combination of means for producing a moving stream of comm'in'uted electrically-conductive material, and means including an inductor disposed adjacent said stream for producing a high frequency alternating magnetic field acting on said stream to deflect conductive particles from said stream by the reaction with said field of'high frequency eddy currents produced in said particles.

9. The method of separating ore from a crushed mixture of gangue and ore which comprises, flowing the crushed mixture through an alternating magnetic field having a fdrequency greater than 500 cycles per secon 10. The method of separating ore from a meeeeet crushed mixture of ore and gangue, comprising means adapted to receive the mixture and discharge it in a predetermined manner, a coreless coil arranged below said means and adapted to be connected to a source of edter- Hating current and to create when energized a magnetic fielld in the path of the discharged mixture.

In testimony whereof, K afix m ROY inn. 

